Had Focal Seizures, Dizziness, Brain Fogging. Taken Hormonal Replacement Therapy. On Depakote And Tirosint. Continue Medication?

My mother is 92 1/2 years old and had focus seizures (after 1-2 years of taking HRT when she was in her late 70 s to prevent heart disease per her GP), she was put on Depakote. She has been on Depakote (and 2 other seizure drugs) since 2000 and she hasn t had any more seizures that we can tell. She is only on Depakote now for many years. Her dose is 750mg per day taken twice a day (Delayed Release ). This is an increased dose given by her doctor' s partner who saw her for the first time in July 2013. Before she was on 500mg and 750mg every other day. Since this increase, she slept a lot during the day and complains of foggy head and dizziness. She weighs around 121-125pounds. How much longer should she be on Depakote drug or can the dosage be lowered, now that she hasn't had anymore seizures? She is dizzy and has increasingly slower and slower heart rate . Her bp is controlled with Bystolic 2.5mg and oscillates between 140-120/80+ (Systolic readings varies about 20-25points). She also has arrthrymia. We read on WWW.WWWW.WW that these are side effects and that older patients should have a lower dosage than younger adults. She is very healthy and ambulatory , We want to eliminate as many unnecessary drugs to reduce side effects that may contribute to her brain fog and dizziness, hence her quality of life. She is also on a very low dose of Tirosint (13mcg) for her thyroid. Can she get off Depokote safely without her life being threatened, if we can safely say that her focus seizure was brought upon by taking HRT nearly 15 years ago. (an MRi was taken 1 year ago and doctor said that the results are consistent with someone her age).